528
metric rule
(lemmy.ml)
Be sure to follow the rule before you head out.
Rule: You must post before you leave.
US Metric Association - Origin of the Metric System (https://usma.org/origin-of-the-metric-system)
National Institute of Standards and Technology - Metric Policy - https://www.nist.gov/pml/owm/metric-si/metric-policy
https://en.wikipedia.org/wiki/Metrication_in_the_United_States